The present invention generally relates to a gaseous blend of Ox, and a method for applying the gaseous blend of Ox, that can be utilized to significantly reduce the biological load on consumer products such as food products, botanicals and cosmetic ingredients, which have traditionally been treated with commercial sterilants or fumigants such as ethylene oxide, propylene oxide, methyl bromide, hydrogen phosphide, steam (heat), irradiation, and the like.
A number of commercial fumigants are presently used to treat foodstuffs and other stored commodities. The most widely used fumigants are methyl bromide, hydrogen phosphide, and hydrogen cyanide. As disclosed in U.S. application Ser. No. 09/217,581, many of these compounds pose hazardous conditions for application personnel and can form deleterious residues in the foodstuffs and commodities that are treated. Furthermore, some of the traditional fumigants have been identified with the formation of carcinogens and mutagens which thus limit the products that can be treated.
U.S. Pat. Nos. 5,897,841 and 6,027,667 disclose the use of CO2 as a carrier gas for phosphine fumigant.
U.S. Pat. No. 4,889,708 discloses a mixture of phosphine and CO2 and the use thereof to fumigate stored produce, such as grains and other commodities.
U.S. Pat. No. 4,200,656 discloses the use of CO2 as a carrier for methyl bromide in fumigation.
U.S. Pat. No. 4,998,377 discloses the use of CO2 as a carrier for methyl bromide and hydrogen phosphide in fumigation.
U.S. Pat. No. 5,678,352 discloses the use of CO2 as a carrier for toxic agents such as methyl bromide during fumigation.
U.S. Pat. No. 4,989,3 63 discloses application of CO2 in pesticidal quantities for fumigation. The process disclosed in U.S. Pat. No. 4,989,363 require administration of the CO2 for a period of time of at least about 5 days.
Other procedures that have been developed to treat products utilize heat, ionizing radiation, and other chemical compounds. All of these procedures are potentially detrimental to the products"" nutritional, physical and/or chemical attributes and thus make them undesirable. Insects and other pests damage to food products and other commodities account for billions of dollars of losses in the United States annually. Traditionally, a number of fumigants have been utilized to control these pests by their application under air tight tarpaulins, in sealed rooms and in steel chambers. All three primary gaseous fumigants; i.e., methyl bromide, hydrogen phosphide and hydrogen cyanide, are facing major regulatory restrictions and/or total phase out agreements over the next few years. With these limitations in mind, the search for effective alternatives has evolved the use of materials such as methyl iodide and sulfonyl fluoride. Unfortunately, these alternatives have limitations due to factors such as worker exposure, halogen content and damage to certain commodities.
Ozone (O3) and its primary active component, atomic oxygen, have been used in water and commodity sterilization for about 100 years. However, as discussed in more detail below, prior treatment methods using O3 would be ineffective for many applications.
U.S. application Ser. No. 09/217,581 discloses a method and apparatus that uses a gaseous mixture of oxygen-containing gases, i.e., O3, O2 and O1, hereinafter referred to as Ox, to reduce biological loads on consumer products to eliminate pathogens while maintaining product stability.
As an advancement to the invention disclosed in application Ser. No. 09/217,581, the present inventors have surprisingly discovered that for a number of consumer products, Ox biological burden reduction is even more effective at two distinct temperature ranges. With the appropriate adjustments to other parameters, both temperature ranges can be used for enhanced microbiological reduction and insect control, The present inventors have thus discovered that Ox""s effectiveness as a fumigant can be maintained and in some cases enhanced while increasing the treatment temperature. When the temperature is increased, certain other Ox treatment parameters must also be adjusted away from those originally used for microbiological reduction.
It is desirable to treat a wide variety of consumer products in a cost effective manner. The gaseous blend of Ox, and method of the present invention permit fumigation (hereinafter referred to as xe2x80x9cbiological burden reductionxe2x80x9d of a product in its original container (e.g., burlap bag, fiber drum, kraft paper bag, plastic bag, etc.)). Thus, double handling, product loss, and post treatment contamination are reduced.
The gaseous blend of the present invention consists at least in part of O3.
The method of the present invention utilizes the gaseous blend of Ox in a technologically advanced treatment system that overcomes the limitations formerly encountered with O3 treatment on biological burden. Prior O3 treatmnents include, for example, (1) the submersion of an article to be treated in ozone-containing water and the bubbling of ozonated water over the article (see, e.g., U.S. Pat. No. 4,517,159 to Karlson and U.S. Pat. No. 4,640,872 to Burleson); and (2) the static treatment of medical devices and food products with gaseous ozone (see, e.g., U.S. Pat. No. 3,179,017 to Shapiro et al., U.S. Pat. No. 5,069,880 to Karlson, and U.S. Pat. No. 5,120,512 to Masuda.) Systems utilizing such as described above have encountered several limitations. The incorporation of ozone gas into water and then submersion of items(s) to be sterilized or the spraying of ozone treated water onto the surface of item(s) to be sterilized limit the process to products that can be soaked in water. The few gaseous uses of ozone have been limited to the surface treatment of medical devices and the like due to the lack of adequate penetration into compacted products. Thus, although these past processes have proven the efficacy of ozone as a sterilant, the limitation of the use of ozone as a surface treatment has not presented ozone as a reliable sterilant or fumigant for products contained within commercial containers.
In addition to the generation of the ozone molecule, the present invention also utilizes the quenching effect of other inert gases to assist ozone generation, thereby increasing the stability of the Ox radicals. Argon and carbon dioxide (CO2) can be used in the method of the present invention to achieve these factors. Furthermore, the presence of atmospheric nitrogen has been utilized in the food industry for many years to protect sensitive oils and fats from oxidative rancidity. Small quantities of nitrogen can be used in the method of the present invention to assist in the protection of sensitive food components as well as assisting in the stabilization of the Ox generation.
Accordingly, it is an object of the present invention to provide a gaseous blend of Ox and a method for applying the gaseous blend of Ox for reducing biological burden from consumer products.
It is another object of the present invention to provide a gaseous blend of Ox and method for applying the gaseous blend of Ox for reducing biological burden from consumer products in a safe manner.
It is thus an object of the present invention to eliminate the health risks that are associated with the reduction of biological burden from consumer products.
It is a further object of the present invention to provide a simple, efficient and economical gaseous blend of Ox and a method for applying the gaseous blend of Ox for reducing biological burden from consumer products that can be used at the site of production and/or packaging of such products.
In accordance with the above and other objects, the inventive gaseous blend consists of at least O3. The inventive method for applying the gaseous blend comprises applying a continuous stream of Ox gas to a material at a specified temperature. The first temperature range is 45xc2x0 F. to 60xc2x0 F. The second temperature range is 90xc2x0 F. to 130xc2x0 F. In conjunction with temperature, adjustments to other parameters proves beneficial depending on the commodity being treated and organism being targeted. With the eventual elimination of methyl bromide as a fumigant, development of alternative treatment methods has become very important. The present inventors have discovered that Ox""s effectiveness as a fumigant can be maintained and in some cases enhanced while increasing the treatment temperature. When the temperature is increased, certain other Ox treatment parameters must also be adjusted away from those originally used in application Ser. No. 09/217,581 for microbiological reduction.
The continuous stream of Ox gas is prepared in an Ox generation cell, which contains a means for generating the Ox gas at a pressure less than about 20 lbs/in2, for example, one or more of the following: corona discharge, high frequency electrical discharge, ultraviolet light, x-ray, radioactive isotope and electron beam.
As discussed herein, N2, CO2 and/or Ar may be added during Ox treatment. The addition of 0%-70% N2, 20%-100% CO2 and/or 1%-18% Ar increases the generation of an Ox quenching effect. Penetration of Ox into the material being treated is thus enhanced. In addition, argon is unique among the (inert) Noble Gases, in that it is soluble in both water and organic liquids. (The Merck Index Eleventh Edition). This characteristic theoretically enables argon to become a glue of sorts. Argon is capable of attaching to gases without reacting thereto. Argon thus assists in Ox quenching by attaching to the Ox molecules and preventing the Ox molecules from colliding into each other. Argon also loosely binds hydrophilic and hydrophobic materials, thus allowing one to be diffused through the other, without reacting with either. This characteristic is useful in accelerating the diffusion of Ox into and through hydrophilic materials such as fats, oils and cell walls.
An apparatus such as that disclosed in application Ser. No. 09/217,581, may be used to carry out the method of the invention.
The apparatus disclosed in application Ser. No. 09/217,581 comprises:
(a) a biological burden reduction chamber;
(b) a vacuum pump coupled to the biological burden reduction chamber;
(c) an Ox generation cell, wherein the Ox generation cell contains a means for generating Ox at pressure less than about 20 lbs./in2 using, for example, one or more of the following: corona discharge, high frequency electrical discharge, ultraviolet light, x-ray, radioactive isotope and electron beam;
(d) a first control valve coupled to the biological burden reduction chamber and the Ox generation cell, wherein the first control valve is capable of permitting Ox to be drawn from the Ox generation cell into the biological burden reduction chamber; and
(e) a second control valve coupled to the biological burden reduction chamber, wherein the second control valve is capable of withdrawing Ox contained within the biological burden reduction chamber out of the biological burden reduction chamber.
Water vapor may be introduced to the gaseous Ox to maintain an appropriate humidity level, i.e., between about 20% and 98% relative humidity, and, more preferably between about 40% and 75% relative humidity. The appropriate humidity level is dependent upon the ambient humidity and upon the product being treated. For example, granular and powered products require a relatively low humidity level to prevent growth of mold and yeast thereon. However, depending on the length of treatment time, any vacuum that may be created during the process removes humidity, thus requiring the addition of humidity. The Ox gas may then be passed through a commercially available catalytic destruct unit to eliminate any residual O3 and O1 before the gas stream is discharged to the atmosphere.
The present invention is also directed to treated consumer products that result from use of the present inventive gaseous blend of Ox and method.
Additional objects and attendant advantages of the present invention will be set forth in the description and examples that follow, or may be learned from using the gaseous blend or practicing the method of the present invention. These and other objects and advantages may be realized and attained by means of the features, instrumentalities and/or combinations particularly described herein. It is also to be understood that the foregoing general description and the following detailed description are only exemplary and explanatory and are not to be viewed as limiting or restricting the invention as claimed.
The invention itself, together with further objects and attendant advantages, will best be understood by reference to the following detailed description, taken in conjunction with the accompanying drawings.